To achieve maximum yield, crops require adequate supply of essential plant nutrients. This supply needs to replenish nutrient deficiencies as well as the plant’s own inefficiency to source available nutrients (due to soil and environmental factors). The decision on how much fertilizer to apply is complex, as many factors are outside the farmer's control. However an approximate rate of fertilizer application can be formulated from the following:
Computer models that can accept this information are used to generate the optimal application rate. Once the correct rate has been established, placement and timing of application must be considered.
